It has been found desirable to provide portable door locking devices. Such devices are particularly useful by travelers who desire the extra security of a door lock which is completely internally operated. These devices are also particularly desirable for use with doors not having locks.
Prior portable or otherwise easily installable and removable door lock devices have suffered from numerous drawbacks. In particular, some of these devices are not completely self-contained in the sense that something must be done to the door or frame to enable one to use the lock. For example, padlocks and the like are easily engageable and removable from a door. On the other hand, to allow the padlock to be useful, tabs or metal loops or the like must be secured to the door and frame.
Numerous self-contained door locks have been devised to lock a door without any modification of the door. Unfortunately, these locks have not been extremely useful in their locking capacity, or have not been simple in their design and use.
For example, U.S. Pat. No. 3,494,653 to Steele discloses a door locking device which includes a strap for engaging a door, and a rotatable engaging pin located thereon. Unfortunately, while the device is easy to use, because the pin can rotate about a point on the strap, excessive pressure on the door can cause the pin to rotate away from the door, allowing it to be unlocked.
U.S. Pat. No. 1,429,536 to Robinson discloses a device which includes a strap which engages a recess, and a clip which is attachable to the strap on which is located a door engaging bolt. Unfortunately, this design suffers from several drawbacks. In particular, high enough pressures against the door could result in the clip releasing from the strap, thus unlocking the door.
Further, this clip with the bolt thereon must be removed from the strap each time the door to be locked (or unlocked) is opened or closed. This is not only inconvenient, but presents many opportunities for the clip to be lost. Lastly, in order for the clip to be easily detachable from the strap, it must be made quite springy, which allows it to be more easily dislodged during use. On the other hand, if the clip is rigid enough to remain in the strap, it is not easily removable by hand.
Further, U.S. Pat. No. 5,193,867 discloses a door locking device which comprises a clip attached to a strap. Unfortunately, this lock design suffers from several drawbacks. Primarily, the clip may only engage the door at discrete intervals, often preventing the door from being closed as tightly as desired. This is a serious drawback. For example, often the door lock is not simply used to prevent opening of a door a sufficient distance to allow a human therethrough, but is used to secure a door completely shut. Such may be the case where the door is exposed on the outside to the elements and is not properly weather-proofed. In such instances, it is desirable to press the door as tightly as possible against the frame to prevent insects, drafts, or water, from passing by the door.
There is thus a need for a door lock which is easily installed on a door and removed therefrom, which securely holds a door shut, and which is of a simple design.